revert(io): restore gocloud/s3.go comments

Author: alessandro-nori

io/gocloud/s3.go

@@ -45,12 +45,14 @@ var unsupportedS3Props = []string{
 
 // ParseAWSConfig parses S3 properties and returns a configuration.
 func ParseAWSConfig(ctx context.Context, props map[string]string) (*aws.Config, error) {
+	// If any unsupported properties are set, return an error.
 	for k := range props {
 		if slices.Contains(unsupportedS3Props, k) {
 			return nil, fmt.Errorf("unsupported S3 property %q", k)
 		}
 	}
 
+	// Remote S3 request signing is not implemented yet.
 	if v, ok := props[io.S3RemoteSigningEnabled]; ok {
 		if enabled, err := strconv.ParseBool(v); err == nil && enabled {
 			return nil, errors.New("remote S3 request signing is not supported")
@@ -100,15 +102,18 @@ func ParseAWSConfig(ctx context.Context, props map[string]string) (*aws.Config,
 	return awscfg, nil
 }
 
-// resolveUsePathStyle determines whether the S3 client should use path-style addressing.
-// It defaults to virtual-hosted style for standard AWS S3 and path-style for custom endpoints.
+// resolveUsePathStyle determines whether the S3 client should use
+// path-style addressing. It defaults to virtual-hosted style for
+// standard AWS S3 and path-style for custom endpoints (e.g. MinIO).
+// The s3.force-virtual-addressing property can override either default.
 func resolveUsePathStyle(endpoint string, props map[string]string) bool {
 	usePathStyle := endpoint != ""
 	if forceVirtual, ok := props[io.S3ForceVirtualAddressing]; ok {
 		if cfgForceVirtual, err := strconv.ParseBool(forceVirtual); err == nil {
 			usePathStyle = !cfgForceVirtual
 		}
 	}
+
 	return usePathStyle
 }
 
@@ -139,6 +144,7 @@ func createS3Bucket(ctx context.Context, parsed *url.URL, props map[string]strin
 		o.DisableLogOutputChecksumValidationSkipped = true
 	})
 
+	// Create a *blob.Bucket.
 	bucket, err := s3blob.OpenBucketV2(ctx, client, parsed.Host, nil)
 	if err != nil {
 		return nil, err